--- title: "Linux Telemetry Schema - Workshop Docs" description: "Linux Telemetry Schema - Enterprise control plane for Santa. Manage rules, approvals, telemetry, and policies across your macOS fleet." doc_version: "1" last_updated: "2026-09-02" canonical: "https://northpole.security/docs/workshop/linux" --- # Linux Telemetry Schema This page documents the complete schema for all telemetry event types collected by Workshop from Santa agents on Linux. Each event type below is also the table name in SQL queries, prefixed with `linux_`: exec fields live in `linux_exec_2026`, `linux_exec_202603`, or `linux_exec_20260315` (see [table naming](https://northpole.security/docs/workshop/telemetry#table-naming-convention)). The prefix exists because `fork` and `exit` are collected on macOS too, with entirely different columns. Columns drift across Santa versions, so `DESCRIBE linux_exec_20260315` on your own data is the authoritative list. Nothing on this page is shared with the [macOS schema](https://northpole.security/docs/workshop/telemetry/schema/macos), including the base fields. A field with the same name on both platforms does not necessarily mean the same thing, and a query written against one platform will not run against the other. ## Base Fields Field Type Description EventID text Unique identifier for the event MachineID text The unique machine ID (host UUID) Hostname text The hostname of the machine at the time of the event BootID text The kernel’s boot identifier, stable for the lifetime of one boot EventTime timestamp When the event occurred ProcessedTime timestamp When Workshop processed the event OperatingSystem text The platform the telemetry came from, always `linux` in these tables ## Process Events These are the events that make up the lifecycle of a process: it is created by `linux_fork`, replaces itself with a new program by `linux_exec`, and ends by `linux_exit`. ### linux\_fork A process creating another process. `SharedThreadGroup` is what separates a new thread of the same program from a genuinely independent process, and it decides that on its own. `SharedMm` and `SharedFiles` each report one resource shared independently of that: a thread commonly shares both, but neither is required for thread-group membership, and either can be shared by a task that is a separate process. Field Type Description Subject Lineage The process performing the creation, with the process that started it Object Process The newly created process SharedThreadGroup boolean Whether the new task joined its creator’s thread group, making it a thread of the same program SharedMm boolean Whether the new task shares its creator’s address space SharedFiles boolean Whether the new task shares its creator’s file descriptor table Container Container The container the subject ran in. Absent when it ran directly on the host ### linux\_exec A process replacing itself with a new program. Field Type Description Subject Lineage The process performing the execution and the process that started it, as they are after the change took effect Comm text The short name the new program will be known by, at most 16 characters. Chosen by the program, so not evidence of what ran Executable File The canonical path of the executable image that actually ran Invoked File What was asked for. For a script this is the script, where `Executable` is the interpreter Interpreted boolean Whether `Invoked` and `Executable` differ because an interpreter handled the request WorkingDirectory File The working directory, needed to make sense of any relative path in `Args`. Only `Path` and `Type` are populated Root File The process’s root directory, which is how a process confined to a subtree becomes visible. Only `Path` and `Type` are populated FileDescriptors FileDescriptor array The standard descriptors the program inherited Tty Tty The terminal the process is attached to Args text array Command-line arguments Envs text array Environment variables Argc number An upper bound on how many entries `Args` holds, not a guarantee ArgvEnvpCopied number Bytes of arguments and environment captured. Zero when capture failed outright ArgvEnvpTruncated boolean When set, the absence of an expected argument means nothing Container Container The container the subject ran in. Absent when it ran directly on the host ### linux\_exit A process terminating. `Signal` is meaningful only when `ExitFromSignal` is set, and `ExitStatus` only when it is not. `ExitCode` is retained so nothing is lost, but it cannot be interpreted without `ExitFromSignal`; read the decoded fields instead. Field Type Description Subject Lineage The terminating process, with the process that started it ExitCode number The raw packed status value a waiting parent receives ExitFromSignal boolean Whether the process was killed by a signal rather than ending on its own Signal number The signal that killed the process ExitStatus number The status the process chose to end with CoreDumped boolean Whether a memory dump was started, not that one was completed or written anywhere GroupDead boolean Whether a whole program ended, as opposed to one thread of a still-running program Container Container The container the subject ran in. Absent when it ran directly on the host ## Common Nested Types The following types are used throughout the Linux telemetry schema to represent shared data structures. ### Credentials The identity a process runs as. Two sets are carried on every process: the real set records who started it, the effective set is what permission checks are made against, so a program that has changed identity is still attributable to whoever launched it. Field Type Description UID number The real owner of the process, and who is able to signal it GID number The real group of the process SUID number Saved user ID, which a process that has dropped privilege can return to SGID number Saved group ID, the group equivalent of `SUID` EUID number The process’s privileges for most non-filesystem access EGID number The group equivalent of `EUID` FSUID number The identity used when accessing filesystem objects FSGID number The group equivalent of `FSUID` CapInheritable number Inheritable capability set, as a bitmask CapPermitted number Permitted capability set, as a bitmask CapEffective number Effective capability set, as a bitmask CapBounding number Bounding capability set, as a bitmask CapAmbient number Ambient capability set, as a bitmask Securebits number The securebits flags in force for the process ### Namespaces The isolated views of system resources a process sits in. Each value identifies one view: two processes sharing a value share that resource, and differing values are the clearest signal that a process is isolated from the host, whether by a container runtime, a sandbox, or a program that has isolated itself. These are operating system namespaces and have nothing to do with the Kubernetes namespace on KubernetesPod. Field Type Description UTS number Hostname and domain name IPC number Shared memory, semaphores and message queues Mnt number Which filesystems are mounted, and where PID number Which other processes are visible, and under what numbers PIDForChildren number The view processes started from here will be placed in. Differs from `PID` only between requesting a new view and starting the first child Net number Network interfaces, addresses, routes and ports Time number The system clock offsets a process observes TimeForChildren number Same requester-versus-children distinction as `PIDForChildren` Cgroup number How much of the resource-control hierarchy is visible from here User number How user and group identities map to those on the host, which is how an unprivileged user can appear as an administrator inside a container CgroupID number The specific resource-control group the process belongs to, as opposed to `Cgroup`, which describes only what it can see. The primary key for attributing a process to a container ### Process A running program, or one thread of it. PID alone does not identify a process over time because process numbers are recycled; PID together with `StartBoottime` does, within one boot of the host. Build identity on `StartBoottime` rather than `StartTime`, which is derived from the wall clock and inherits its error. Field Type Description PID number Process ID as seen from the host NSPID number Process ID as seen inside the process’s own PID namespace TGID number Thread group ID, the ID of the program this thread belongs to NSTGID number Thread group ID as seen inside the process’s own PID namespace StartBoottime number Nanoseconds since boot at which the process started StartTime timestamp Wall-clock time the process started PGID number Process group ID SID number Session ID LoginUID number The user who logged in, surviving later changes of identity. `4294967295` when unset SessionID number An identifier for that login. `4294967295` when unset RealCredentials Credentials The identity the process was started with Credentials Credentials The identity the process runs as now Namespaces Namespaces The kernel namespaces the process sits in Executable File The running program. Only `Identity` is populated here NoNewPrivs boolean Whether the process is barred from gaining privileges through `exec` ### Lineage A process together with the process that started it, captured at the same moment so the pair is internally consistent. Field Type Description Task Process The process itself Parent Process The process that started it ### Filesystem The filesystem a file resides on. Where a file lives is often as telling as what it contains: an executable on an in-memory or layered filesystem did not come from the host’s own installation. Field Type Description Type text Coarse filesystem type, e.g. `FILESYSTEM_TYPE_OVERLAYFS`, `FILESYSTEM_TYPE_TMPFS` Magic number The exact filesystem magic value the kernel reported, set even when `Type` is unknown ### FileIdentity What distinguishes one file from another independently of the name it is reached by. Two observations agreeing on `Dev` and `Ino` describe the same file even under different paths; agreeing on `Size` and `Mtime` as well means it has not changed in between. Field Type Description Dev number Device ID Ino number Inode number Size number File size in bytes Atime timestamp Last access time Mtime timestamp Last modification time Ctime timestamp Last status change time ### Digest A measurement of a file’s contents, which is what allows the same binary to be recognised wherever it appears and however it is named. Field Type Description Algorithm text Digest algorithm, e.g. `HASH_ALGORITHM_SHA256` Value text Hex-encoded digest value Valid boolean False when no measurement was available, in which case the other fields are meaningless ### File Everything known about a single file. Any observation populates the subset it actually has, so an absent field means “not observed”, never “observed to be empty”. Field Type Description Path text File path Identity FileIdentity Device, inode, size and timestamps Type text The kind of file, e.g. `FILE_TYPE_REGULAR` Filesystem Filesystem The filesystem the file resides on Digest Digest Measurement of the file’s contents Deleted boolean Whether the file had already been removed when it was observed. Null when the file itself was not inspected PathTruncated boolean Whether `Path` ran out of room before it was complete. Null exactly where `Path` was not observed ### FileDescriptor A numbered channel a program inherited when it started. Only 0, 1 and 2 are reported. A pipe or socket where a terminal is expected is a strong indication that a program’s output is being captured. Field Type Description FD number File descriptor number File File What the descriptor refers to ### Tty The terminal a process is attached to. Field Type Description Major number Major device number Minor number Minor device number Name text Terminal device name Present boolean False for a service, which has no terminal; the other fields then carry nothing ### Image The image a container was created from. Field Type Description Reference text The image reference, which is mutable and reusable Digest text The image digest, which is stable and always means one image ### WorkloadOwner What ultimately created and owns a pod. A pod’s own name is generated and replaced every time it is rescheduled, so this is the durable identity to attribute activity to. Field Type Description Kind text Controller kind, e.g. `Deployment`. Clusters routinely add their own kinds Name text Controller name ### KubernetesPod Where a container sits within an orchestrator, populated only when the host is managed by one. `Namespace` here is a Kubernetes namespace, a tenancy boundary within a cluster, which is a wholly different concept to the kernel Namespaces on a process. Nothing relates the two. Field Type Description Name text Pod name, regenerated whenever the pod is rescheduled Namespace text Kubernetes namespace the pod runs in UID text Pod UID ContainerName text Name of the container within the pod Owner WorkloadOwner The controller that owns the pod ServiceAccount text The identity the pod’s processes present to the cluster ### Container The container an event occurred inside. `CgroupPath` is observed directly and is present whenever the activity happened inside any resource-control group. Everything below it is resolved against the local container runtime and is absent when the runtime is unknown or unreachable, or when the activity did not happen inside a container at all. Field Type Description CgroupPath text The cgroup path the activity happened in Runtime text The container runtime, e.g. `CONTAINER_RUNTIME_DOCKER` ID text Container ID Name text Container name Image Image The image the container was created from Labels map(text, text) Labels attached at creation, carried whole Pod KubernetesPod Orchestrator attribution, when the host is managed by one ## Sitemap - [Home](https://northpole.security/index.md) - [Workshop](https://northpole.security/workshop.md) - [Santa](https://northpole.security/santa.md) - [Features](https://northpole.security/features.md) - [Cookbook](https://northpole.security/cookbook.md) - [Docs](https://northpole.security/docs.md) - [Blog](https://northpole.security/blog.md) - [Glossary](https://northpole.security/glossary.md) - [About](https://northpole.security/about.md) - [Contact](https://northpole.security/contact.md)